Abstract

MicroRNAs are a class of small non-coding RNA that play an important role in gene regulation either by cleaving or repressing the translational process of mRNA. This study
focuses on the temporal expression of three miRNAs, namely miR156, miR159, and miR535, on different developmental stages of the pineapple fruit Total RNA was extracted from six different developmental stages of pineapple (week 0, week 4, week 12, week 16 and week 20). Subsequently, the miRNAs were amplified using stem-loop mediated RT-PCR and the level of microRNAs gene expression was quantified using RT-qPCR. The 4 values were analyzed by using the 2-MO method and the expression pattern of miRNAs was examined. The result shows that the expression pattern of miR156 and miR535 fluctuates during maturation With, both miRNAs being highly expressed in early development stages and down regulated during ripening. On the other hand the expression of miR159 gradually declines upon the onset of ripening. This pattern is in agreement with the hypothetical target genes of the three miRNAs where miR156 targets Squamosa Binding Protein, miR159 targeting GAMYB-like genes, miR535
is predicted to target xytoglucan endotransglucoxylase. The temporal expression pattern of these miRNAs revealed their Importance during the pineapple fruit development